宁夏白芨滩地区风沙土理化性质初步研究

为了研究宁夏河东沙区白芨滩地区风沙土的理化性质,通过野外调查、采样及室内实验分析,对研究区流动沙丘、半流动沙丘及草方格固定沙丘风沙土理化性质进行了测定分析。结果表明:土壤含水量均较低,土壤含水量的平均值表现为草方格固定沙丘半流动沙丘流动沙丘。风沙土土壤粒度组成表现为各层均以细沙颗粒为主,中沙颗粒含量次之,极细沙含量较小。流动沙丘的表层含有非常少量的粗沙颗粒,半流动沙丘和草方格固定沙丘各层几乎没有粗沙颗粒。而草方格固定沙丘的表层含有少量的粉沙颗粒,其余各层均无粉沙颗粒。土壤容重从表层向下逐渐减小,流动沙丘和半流动沙丘容重较为接近,而草方格表层沙土容重明显较小。土壤养分流动沙丘、半流动沙丘和草方格固定沙丘的养分含量较接近,差异不显著,而且各类型沙丘养分的垂直变化无明显规律,变化不稳定。     

新型平房仓环流熏蒸系统环流效果的研究

对我国新建平房仓的固定式和移动式两种环流装置进行了实仓环流效果的试验研究，结果表明，新建平房仓的环流熏蒸系统可使磷化氢气体在较短的时间内穿过深层粮堆，一般可在施药开始后8-17小时内使磷化氢气体在全仓达到均匀分布。上层和空间的磷化氢浓度达到均匀一致即表明整个粮堆浓度达到了均匀分布。同时发现，通风道的形式及平衡调节、粮堆内的温差及仓房的气密性都会影响环流效果。     

Application of Coordinate Difference Method in Safe Monitor of High Slope with Total Station Actively

The most common used method for safe monitor of high slope is to set a fixed observation point to monitor the transformation. But in urban area, due to restriction of the site and telecommunication conditions the transformation of high slope may have an impact to the fixed point and the result and the result we take from the point may be not correct. To avoid the impact and improve the accuracy, in this paper, a coordinate difference method to monitor the transformation of high slope with Total station actively is put forward and the principle, error analyses of this method are described and its application in safe monitor of high slope is introduced.     

Design and Realize the Short Message Service System

Along with the widely using of mobile telephone, the SMS (Short Message Service) has achieved more and more approbation of consumers. Besides the point-point application of SMS among mobile phones, a new application of SMS between information system and mobile phones is developed quickly now, and it is a new way to achieve information conveniently and duly for users. In this paper, we design a software based on SMS to solve some problems which exists in the communication among employees. We also give out the system's functions, key technology and application in the enterprises. This system has some important value in theory and application for building a digital enterprise.     

Memory Accessing Mechanism of X86 Computer System In Protected Mode

Protecting mode is on importmant working method of X86_based computer system,which provides the hardware support for multi_task and multi_process operation system on X86 platform. During the low_level development of X86_based computer system,it is very important to understand the working method of memory that is a main part of computer system. This paper discusses the data structure and hardware component of X86_based computer system which support the two mechanism of accessing memory:segmenting and paging,as well as the process of converting logical address to linear address and mapping virtual address to physical address. Througn segmenting and paging mechanism,we can realize the independent address space for every process in multi_process system,as well as the measure for protecting the system memory which can prevent the system breakup caused by illegal memory access.     

Intrusion Detection Technology in Ad Hoc Network

With the rapid development of wireless network and mobile computing,the security of network becomes more important.As one of wireless mobile network,mobile Ad hoc network has new vulnerabilities that do not exist in a fixed wired network,and is susceptible to attacks.This paper introduces some methods which used in intrusion detection system and provides a new model of system based on multi-layer integrated distributed technology,especially recommend the protocol analyzing method in this system.     

Kinematics and Dynamics Analysis on the Mobile Mechanism of a Micro Piping Robot

A micro piping robot is able to help people finish tasks such as inspection inside a mini pipe. Research on the mobile mechanism of the robot is very important in the robot researching area. The kinematics and dynamics characteristics of the mobile mechanism for a planetary gears driven micro robot have been studied. The operation, the principle and the affect factors of the mobile mechanism have been discussed in detail. In order to drive the robot well, the adhesion and the power of the mobile mechanism should be increased as the influence of its autoeciousness power has been reduced.     

Study on Broadband Cellular Mobile Communication System OFDM Based

The characteristic of broadband mobile channel is analyzed, then we construct a model of bidimensions wideband mobile channel based on delay and Doppler frequency domain. On the basis of describing OFDM theory, the design on initial physical layer of broadband cellular mobile communication systems is proposed. Simulation for base band system is ground on channel model proposed above. The results of experiment and simulation are relatively inosculated, which manifest the well prospect of the communication system proposed for future application.     

Application of Green Construction in China:Current State and Promotion Measures

Green construction is the main embodiment of application of sustainable development strategy in construction process and is the important part of sustainable construction industry. In this paper, the current state and shortage concerning the green construction in China are described, followed by analyzing the reasons from the viewpoint of cognitions, technique, cost, management and regulation. In this paper, recommendations on countermeasures promoting the application of green construction in China are put forward, which include enhancing the consciousness of participant on green construction, mitigating the economic barriers to application of green construction, establishing and perfecting the regulations as well as setting up the assessment system on green construction.     

Estimation Methods for DOA Based on Smart Antenna

Smart antenna is one of the key technique in the third generation mobile telecommunication system. Main estimation methods for DOA(direction of arrival),i.e. ESPRIT, MUSIC, WSF, Mininorm,etc., are researched,the performances for DOA estimation based on smart antenna are analyzed by the research of theory, simulation experiment and the contrast algorithms between and Cramer Rao Bound.The research results aren't only propitious to research and develop for smart antenna,but also for the application of smart antenna in mobile telecommunication.     

Distributed Generation of Shared RSA Keys in Mobile Ad Hoc Networks

Mobile Ad hoc NETworks(MANET) is a totally new concept in which mobile nodes are able to communicate together over wireless links in an independent manner,without needing any fixed physical infrastructure and centralized organizational/administrative infrastructure.However,the nature of ad hoc networks makes them very vulnerable to security threats.Generation and distribution of shared keys for CA(Certification Authority)is challenging in security solution based on distributed PKI/CA.Those solutions that have been proposed in the literature and some issues are discussed.This paper propose the solution of distributed generation of shared CA keys based on threshold RSA cryptosystems,with which the security and robustness of system is enhanced.     

Improvement Methods of Fuzzy Control with Intelligent Integration

Fuzzy controller can achieve satisfactory dynamic performance even for complicated process without mathematical model of the process.Its main imperfection is the existence of steady state error and ultimate oscillatory in the process output. This limits its application area. How to eliminate the steady state error while keep its good dynamic performance has been paid much attention. The strategy to introduce integral function to the conventional fuzzy control system is put forward in this paper to overcome the above problem. After expound two key factors on introducing integral action,an intelligent integral algorithm has been employed,and two methods on introduction of the intelligent integral to the fuzzy control system are proposed. Their characteristics and applied situations are summarized.     

不同灌溉方式对两个马铃薯品种生理特性和水分利用效率的影响

研究了两个抗旱性不同的马铃薯品种(荷兰15号和克新1号）在不同灌溉方式下的生长、生理特性和水分利用效率。结果表明, 不同灌溉方式对马铃薯生理指标有显著影响。隔沟交替灌溉区的植株株高和叶面积高于常规灌溉区和固定隔沟灌溉区。隔沟交替灌溉提高了干旱胁迫应答抗氧化酶过氧化物酶（POD）、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的活性,而反映胁迫受害程度的丙二醛（MDA）浓度均低于常规灌溉和固定隔沟灌溉处理。在隔沟交替灌溉条件下,克新1号的产量比常规灌溉提高了3.84％,水分利用效率比对照提高了35%。荷兰15号的产量与常规灌溉没有显著差异,水分利用效率比对照提高了28%。由此得出,在马铃薯生产中应用隔沟交替灌溉技术具有较大的节水增产潜力,其中克新1号是水分利用效率高、抗旱性强的品种。     

Discussion on Whole Process Marketing Strategies System of Real Estate

In China, the spare commercial housing area is continuously increasing at present. But most people don't satisfy their present living conditions, they want to enlarge the housing areas and to ameliorate their living environment. So there has a contradiction between the people's living level and their requirement. In this paper the whole process marketing strategy system of real estate was put forward to solve the problem. That is, a series of marketing strategies such as pricing strategy, promotion strategy etc were suggested.     

控释复合肥对黄瓜产量及品质的影响

为了提高蔬菜生产中的养分管理水平,实现蔬菜生产的高产优质和可持续发展,采用田间试验研究控释复合肥对黄瓜产量、养分吸收及果实品质的影响。控释肥处理氮磷钾用量较常规施肥减少50%,其中20%的控释复合肥在育苗时与基质混合育苗,然后带肥移栽,其余80%控释肥采用条施的方式底施。结果表明：控释复合肥处理较常规育苗的黄瓜幼苗株高和叶片叶面积分别增加13%和12%。与常规施肥相比,施用控释复合肥的黄瓜产量提高14.1%,氮磷钾养分吸收量分别增加17.0%、11.1%和14.8%,硝酸盐含量降低11.9%。     

Einfluß des Zeitpunktes der K-Düngung auf die Dynamik des nach der Gülledüngung spezifisch gebundenen NH4-N der Tonminerale*

Influence of the time of K fertilization on the dynamics of NH₄-N fixed by clay minerals after slurry application In a pot experiment with topsoil and subsoil of a luvisol derived from loess the influence of the time of K fertilization on the fixation of NH₄-N supplied with slurry as well as on the leaching and the availability of NH₄-N fixed by clay minerals after slurry application was investigated. The following results were obtained: In both soils K fertilization before slurry application resulted in a reduced fixation of the added NH₄⁺.In the topsoil 8 % of the NH₄⁺ supplied with the slurry could be detected in spring as nonexchangeable NH₄⁺ when slurry was added in October and 13 % when slurry was added in January in the treatment K after slurry, when in the treatment K. before slurry the NH₄⁺ fixed after slurry application had been mobilized totally. In the subsoil 45 % of the NH₄⁺ fixed after slurry application in October were mobilized until spring in the treatment K before slurry and only 20 % in the treatment K after slurry. When slurry was applied in January 30 % and 12 %, respectively, were mobilized. In spite of the reduced nitrogen leaching in the treatments K after slurry yield and N uptake of grass were lower as compared to the treatments K before slurry.     

民勤绿洲-荒漠过渡带微区土壤水分及粒度特征研究

为阐明民勤沙区3种典型微区土壤水分及其粒度特征变化,在其产流区及积水区采用土壤剖面及多点混合取样法取样,供土壤水分及理化性质分析,研究结果表明：（1）3类微区积水区积水痕迹明显且其植被盖度大于产流区。粘土沙障 梭梭林积水区结皮发育优于产流区,白刺沙包丘间低地及粘土平地与其结果恰好相反。（2）固定白刺沙包丘间低地积水区各层水分优于产流区;粘土平地表层土壤含水量积水区明显好于产流区,而粘土沙障 梭梭林表层土壤含水量产流区好于积水区。（3）3类微区积水区土壤含水量在20~40 cm之间最低,其中固定白刺沙包丘间低地明显高于粘土平地和粘土沙障 梭梭林,而对应产流区土壤最低含水量大小及出现深度基本一致。（4）固定白刺沙包丘间低地积水区表层粘、粉粒含量小于产流区,而深层细砂粒含量产流区大于积水区;粘土平地两区土壤组成以粗、细砂粒为主,粘粒在各对应层产流区都好于积水区。粘土沙障 梭梭林以粗砂粒为主,结构较为单一。总之,微区通过调节降水的分配方式来影响土壤水分及粒度分布进而影响沙地微区植被时空分布。     

山东省耕地变化与人口增长及经济发展间的关系初探

选择GDP增长率、人口增长率和耕地面积减少率作为主要分析指标,分析了1978—2000年山东经济增长,人口增长和耕地面积减少之间的关系,并选用1991—2000年的数据以市为单位探讨了区域差异。发现改革开放以来的20几年,耕地面积大量减少的时间和经济过热的增长阶段基本同步,具体受固定资产投资规模的牵动。认为经济增长是耕地面积减少的主要宏观驱动因子。     

A Correspondent Node Binding of Method Based on Early Binding Updates Option

The mobile IPv6 protocol solves the mobile communication problems in the next generation Internet.The mobile IPv6 not only provides huge address space,but also strengthens handover ability of mobile user,and realizes route optimization.IPv6 will become the next generation Internet protocol;so the mobile IPv6 will be widely used in the next generation Internet.The moblile IPv6 will provide in the future network,a uniform transmission platform that transmits data,voice data and video data,or other services.People not only put forward more and more requirements for multimedia playing operation,but also bring forward higher request,which is interaction capabiliby communication,Because the long latency associated with mobile IPv6's return routability procedure of correspondent node binding,this paper presents a fast correspondent node binding of method based on early binding updates option.The method not only eliminates at least 50% of the additional delay that a standard correspondent node binding adds to the network stack's latency,but also reinforces the ability to support alternant real-time application.     

基于SWOT-PEST分析的江苏省休闲农业可持续发展研究

以江苏省休闲农业为例,分析发展环境和制定发展战略,为江苏省甚至全国休闲农业发展提供理论支撑。本研究采用SWOT-PEST方法,从政治、经济、社会、技术4个方面对江苏省发展休闲农业的优势、劣势、机遇及挑战进行分析。2019年,江苏省休闲农业接待游客2.3亿人次,综合收入680亿元,休闲农业品牌总数居全国前列。江苏省发展休闲农业具有农业资源多样、区位优势明显、经济实力强劲、信息技术广泛应用等优势和机遇,但存在区域发展不平衡、缺乏科学规划、专业人才紧缺等问题,也面临市场竞争加剧、生态环境威胁、缺乏创新创意等威胁。针对江苏省休闲农业发展存在的问题,构建了SWOT-PEST分析矩阵,提出发展型、扭转型、多样化、防御性4种可持续发展策略。